Electric meter.



G. E. STEVENS. ELECTRIC METER. APPLICATION FILED we. 31, 1905.

Patented Mar. 28, 1911'.

I 4 SHEETS-SHEET 1.

' Inventor; rjge El. Steyens, M//

j wallumimu Witnesses:

G. E. STEVENS. ELECTRIC METER. APPLICATION FILED AUG. 31. 1905.

988, 042. Patented Mar. 28, 1911. x

4 SHEETS-SHEET 2Q rm: mmms PETERS'CO-, wxsumaron, b. c.

G. E. STEVENS.

ELECTRIC METER. APPLICATION FILED AUG. 31, 1905.

Patented Mar. 28, 1911.

4 SHEET$-SHEET 3.

Inventor; Geor eEStevens W o tty Witnesses:

rm: NoRRls PETERS ca :usamcrou, o. c.

G. E. STEVENS. ELECTRIC METER. APPLICATION FILED AUG. 31, 1905.

Patented Mar. 28; 191.1.

4 SHEETSSHEBT 4.

Witnesses:

n1: NuRRrs PETERS r-o., WASHINGTON, v. c.

GEORGE E. STEVENS, OF LYNN, MASSACHUSETTS, ASSIGNOR T0 GENERAL ELECTRICCOMPANY, A CORPORATION OF NEW' YORK.

ELECTRIC METER.

Specification of Letters Patent.

Patented Mar. 28, 1911.

Application filed. August 31, 1905. Serial No. 276,503.

To all whom 'it may concern:

Be it known that I, GEORGE E. STEVENS, a citizen of the United States,residing at Lynn, county of Essex, State of Massachusetts, have inventedcertain new and useful Improvements in Electric Meters, of which thefollowing is a specification.

This invention relates to electric meters and more particularly tointegrating electric meters of the commutating motor type.

The object of the invention is to effect certain improvements in metersof this type whereby the construction is simplified and strengthened,the cost of production reduced and the general operation of the meterunder all the conditions of use improved.

The novel features of my invention will be definitely indicated in theclaims appended hereto.

The details of construction and the mode of operation of my improvedmeter will be better understood by reference to the followingdescription taken in connection with the accompanying drawings whichshow the preferred embodiment of the invention and in Which- Figures 1,2 and 3 are front, side and top views, respectively, of the meter withthe casing in section; Fig. 4t is a section of the supporting tube;Figs. 5 and 6 are sections on lines 5-5 and 6-6, respectively, of Fig.4; Fig. 7 is a section of the shaft; Figs. 8 and 9 are sections on lines8-8 and 99, respectively, of Fig. 7 Fig. 10 is a section of a modifiedform of lower bearing; and Fig. 11 is a section of a furthermodification of the lower bearing.

Referring to the drawings, the meter is inclosed within a suitablecasing 1 consisting of a back and cover having supports secured theretofor fastening the meter to a wall or panel. Secured to the back of themeter are two supporting arms 2 and 3 carrying a large metallic tube 4,and all the parts of the meter are supported on these arms and the tubeso that they can be readily assembled in position and the supportingstructure then secured to the casing. In the outer end of arm 2 and inthe outer end of an arm 5 carried by the support 3 are bearings for theshaft 6 of the meter which carries the armature 7 and commutator 8 ofthe motor, the worm 9 which drives the register and the disk 10 of thedampingmechanism. The armature 7 is preferably of spherical conformationand consists of a hollow supporting member having projections thereonand armature coils wound about the supporting member and spaced apart bythe projections, leads being taken off from the armature coils forconnection to the segments of the commutator. The shaft 6 is preferablyof tubular form as shown in Fig. 7 in order to get great strength withlight weight and is contracted at the proper positions for thecommutator and worm. In the construction of the commutator 8, thecontracted portion of shaft 6 is insulated by wrapping fibrous material,preferably silk thread 11 thereon; this thread is then coated with japanor some other suitable insulating compound. The segments of thecommutator are then placed in position around this insulated portion ofthe shaft and are secured thereon by wrappings of silk thread about theends of the segments as indicated at 12. The thread 12 and thecommutator segments may be coated again with the insulating compound ifdesired, after which the whole is baked until the compound is hard. Thesurface of the commutator may then be turned down in a suitable machineto make the commutator perfectly cylindrical and if desired some of theinsulating compound may be scraped out from between the segments toleave air spaces and to allow for wear. The ends of the armature coilsare then connected to the ends of the segments of the commutator in anysuitable manner. By this construction the diameter of the commutator canbe greatly reduced and a reduction corresponding thereto is thuseffected in the friction between the commutator and brushes.

The field coils 13 of the motor are carried by a frame 14; which issecured to the tube 4 by a clamp 15. The coils 13 are preferablycircular and are mounted close together and closely encircling thearmature 7 so as to reduce to a minimum the number of stray lines offorce. The coils are made of ribbon conductor wound on edge with theseveral turns insulated one from another and each coil consists of twoconcentric coil sections as shown in Fig. 1. Each of the field coilsconsisting of the two coil sections is of stiff insulating material,though if desired metallic plates may be used and sheets of insulatingmaterial inserted between the coil and the metallic plates. Each of thesupporting plates 16 has a circle of holes punched therein and a longthin strip of flexible insulating material such as a cord 16 is lacedback and forth through the holes in the two plates and between the twosections of a coil preferably in the manner illustrated in Fig. 1. Thecord enters the hole in one of the plates, then passes through the coilbetween the two coil-sections to the second plate, then out through ahole in the second plate; reentering through an adjacent hole in thesecond plate and passing through the coil between the two coil-sectionsto the first plate, and out through a hole therein. In this manner thecord is carried back and forth through the coil all the way around;binding the two plates to each other and to the coil. This cord is drawnvery tight so that the coil is held securely between the two plates;also the cord effectually insulates the two coil sections one from theother and at the same time provides air spaces between them and thusgives good ventilation so that heat is radiated from the coils quiterapidly. One or both of the plates 16 between which each coil 13 is heldis extended beyond the coil and openings are provided in these extendedportions through which the posts or the frame let extend, and nuts 14:secure the coils in position on these posts. In order to compensate forfriction in the meter, an auxiliary field coil 17 is mounted on frame14: in inductive relation to the armature 7 and arranged to beadjustable toward and away from the armature to vary its compensatingeffect.

Current is led to and from the coils of the armature by brushes 18bearing on the commutator 8. Each brush 18 is carried by a holder 19which is pivoted intermediate its ends on a pin 20 mounted in aninsulating bushing on the supporting arm 3. In order to hold the brushesagainst the commutator with the proper tension a spring 21. has its endssecured to the upper ends of the two brush-holders above their pivotsand is arranged to press them outward. In this way the brushes are heldagainst the commutator with a light pressure and the pressure of the twobrushes is always equal.

The worm 9 instead of being cut from the stock of the shaft is formed bywinding a thin metal ribbon on edge helically on the contracted portionof shaft 6 and soldering it thereon. The surplus solder can then beremoved with a suitable tool. Worm 9 meshes with a worm-wheel 22 whichdrives the register 23. The register is mounted on the forward end ofarm 3 and a window 24 is provided in the casing in front of theregister.

The rotation of the moving element of the eeaoee meter is retarded by adisk 10 of conducting material which cuts the lines of force of twopermanent magnets 25 and 26. Each of these permanent magnets is of flatcircular form bent at the middle portion so that approximately half ofthe magnet is above the disk and the other half below the disk. At theends the magnets are bent so as to bring their poles in close proximityto the disk 10. The manner in which the magnets are bent so as to bepart above and part below the disk 10 is best illustrated in Fig. 3 andthe arrangement of the poles-of the magnets is shown in Fig. 1. The twopoles above the disk are of one polarity and the two below the disk ofthe opposite polarity and the poles of magnet 25 overlap somewhat sothat the air-gap between the two poles above the disk is angularlydisplaced from the gap between the two poles below the disk. By thisconstruction of the magnets a very broad but short air-gao between thepoles of opposite polarity is obtained; also the damping mechanism isvery compact and permits of a reduction of the length of the meter. Themagnets are held in position by suitable clamps 27 which are mounted onthe supporting arm 8.

The upper end of shaft 6 is spun over as shown in Fig. 7 and a smallopening, accurately centered, is formed in this turnedover portion toreceive the pivot pin 28 of the upper bearing which is secured in anopening in the end of arm 5. Mounted in the outer end of the supportingarm 2 and arranged to be readily removabletherefrom is a bearing plug 29carrying a jewel 30 on which rests a pivot 31 slidingly mounted in theend of the tubular shaft (3 and pressed downward by a helical spring 32coiled within the shaft so that the moving element of the meter isyieldingly supported.

In Fig. 10 I have shown a modified form of lower bearing in which thejewel is carried by the shaft and supported on a spring and the pivot ismounted in the bearing plug. This arrangement of the parts possesses theadvantage that dust will not settle on the jewel and increase thefriction in the hearing.

In Fig. 11 I have shown a further modified form of lower bearing inwhich the bearing point is at the exact center of the armature so thatthe armature is a sphere revolving on its own center. In thisconstruction the bearing plug consists of a long tube 36 mounted in anysuitable manner upon the supporting arm 2 and extending up within thetubular shaft 6. A jewel S0 is supported upon a spring in the upper endof tube 36 and a pivot-pin 31 is mounted within shaft 6, as shown, withits point at the center of the armature 7. The point about which all themovements of the spherical armature are made is therefore the center ofthe sphere and I have found by experiment that with this arrangement ofthe parts the wear on the jewel is greatly decreased. In this form ofbearing means are provided for lifting the moving element ofi of thejewel when the meter is to be transported. This consists of a sleeve 33mounted to slide vertically on the bearing post and a spring 3starranged to press the sleeve upward to bring it into engagement with theend of shaft 6 and raise the entire moving element. A bail 35 is securedto the sleeve and arranged so that it may be turned to bring the bightof the bail under the end of the arm which carries the bearing plug tohold the sleeve 33 in a retracted position.

In meters of this type it is usual to provide a resistance of largeohmic value which is connected in series with the armature and thefriction compensating coil of the metermotor to cut down the currentflowing in the shunt circuit of the meter. I have found that byarranging this resistance within the meter casing so that the heat givenofi by it when the circuit is closed causes a circulation of air withinthe casing, all the parts of the operating mechanism of the meter arekept at approximately the same temperature under which condition themeter will operate best. In order to obtain this circu lation of air,the resistance may be wound in cylindrical coil and mounted verticallywithin the meter casing; I prefer however to employ the tube 4: which issuppo ted in a vertical position and to mount the resistance wire withinthis tube as shown at 37, Fig. 4e. Openings are provided in the ends oftube l, as shown in Figs. 4, 5 and 6, to permit the free entrance andeXit of air and ample space is provided on each side of the coil 37 sothat the air when heated by the coil may rise through the tube.

I do not wish to be understood as limited to the exact constructionwhich I have illustrated and described herein as many modifications canbe made therein without departing from the spirit of my invention. Suchmodifications I consider within the scope of my invention and aim tocover them by the terms of the appended claims.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is,

1. An electric meter comprising a casing, amotor, a register driverthereby and means for retarding the rotation of the moving element ofthe meter within the casing, a tube open at the ends mounted verticallywithin the casing, and a resistance in said tube.

2. An electric meter comprising a casing, a tube open at its endsmounted vertically within the casing, a rotatable shaft, an armaturecarried thereby, a field coil in inductive relation to the armature, aregister geared to the shaft, means for retarding the rotation of theshaft, and a resistance coiled within said tube and connected in serieswith the armature.

3. In a meter, a tubular metallic shaft having two contracted portionstherein, commutator segments secured about one of the contractedportions, an armature carried by the shaft having its coils connected tothe segments of the commutator, a field coil in inductive relation tothe armature, a worm carried by the shaft at the other contractedportion, and a register driven by said worm.

4:. In a meter, an armature, a field coil in inductive relation thereto,a plate on each side of the coil, and alacing of insulating materialholding the plates and coil tightly together.

5. In a meter, an armature, a field coil, a plate on each side of thecoil, a lacing of insulating material holding the plates and coiltightly together, and a frame to which one of the plates is secured tohold the coil in inductive relation to the armature.

6. In a meter, an armature, a field coil in inductive relation theretoconsisting of a plurality of concentric coil sections, a support for thecoil, and a lacing of insulating material securing the coil to thesupport and spacing the coil sections apart.

7. In a meter, an armature, a field coil in inductive relation theretoconsisting of a plurality of concentric coil sections, a plate on eachside of the coil, and a lacing of insulating material extending betweenthe coil sections and holding the plates and coil tightly together.

8. In a meter, an armature, a field coil of ribbon conductor wound onedge mounted in inductive relation thereto, a plate on each side of thecoil, and a lacing of insulating material holding the plates and coiltightly together.

9. In a meter, an armature, a field coil in inductive relation theretoconsisting of a plurality of concentric coil sections of ribbonconductor wound on edge with the turns insulated one from another, aplate on each side of the coil, and a lacing of insulating materialextending between the coil sections and holding the plates and coiltightly together.

10. In a meter, an armature, a field coil in inductive relation theretoconsisting of a plurality of concentric coil sections of ribbonconductor wound on edge, a plate on each side of the coil, and a cordlaced back and forth between the two plates and between the coilsections to hold the plates and coil tightly together and space the coilsections apart.

11. In an electric measuring instrument, a moving element and means forretarding the movement thereof comprising a plate of conducting materialcarried by the shaft of the moving element and a flat circular permanentmagnet cooperating with the plate the poles of which overlap and whichis bent v the movements thereof comprising a disk of conducting materialcarried by the shaft of the moving element and two flat circularpermanent magnets cooperating with the disk each of which is bentintermediate its ends so that the legs of the magnet lie in ditferentplanes, the magnets being so mounted that the poles of one polarity areon one side of the disk and the poles of the opposite polarity on theother side of the disk.

In witness whereof, I have hereunto set my hand this twenty eighth dayof August, 1905.

GEORGE E. STEVENS.

Witnesses JOHN A. MoMANUs, J12, ROBERT SHAND.

Gopies of this patent may be obtained for five cents each, by addressingthe Commissioner of Eatents,

Washington, D. C.

